Cooling pack composition and method of cooling



United States Patent 3,191,392 COOLING PACK COMPOSITION AND METHOD OF COGLING William R. Donnelly, 903 Washington Ave., Piqua, Ohio N0 Drawing. Filed May 15, 1963, Ser. No. 280,705

18 Claims. (Cl. 624) This invention relates in general to a cooling package and to temperature stabilizing materials therefor. More particularly, the present invention relates to a unitary article and substantially dry charge therefor, for shelf storage which article is capable of being activated on desire to obtain extended periods of cooling.

In many instances, there is a substantial need for convenient means of cooling when one is at remote distances from a source of water or electricity. This is especially the case on hikes and picnics where individuals incur muscle or ligament strains or sprains, bruises, swelling, insect bites, heat exhaustion, etc. and an immediate need for a cold compress arises. In times of national or area disaster, when power lines are down, a particularly great need would exist for source of cooling without recourse to refrigeration or ice. Furthermore, a dry, convenient, cold pack not requiring preparation, refrigeration, or mixing, would be suitable for use as a compress for head aches, tooth aches, tooth extractions, or other similar discomforting ailments. It would also be a convenient aid in industrial, domestic, and athletic first aid kits. Due to its desirable properties, it can also be utilized during recreational activities, to cool tool or beverages.

Accordingly, it is an object of the present invention to provide a convenient unitary cooling package not requiring a source of electricity, refrigeration, or addition of water preparatory to its utilization.

A further object of the present invention is the provision of a cooling package and composition contained therein that is suitable as a cold compress wherever the same was previously utilized.

Yet another object of the present invention is the provision of a unitary, bi-segmented, cooling package that on mixing of the ingredients contained in the two compartments there is formed a semi-fluid gelatinous product that will conform to and absorb heat from any animate or inanimate body to which it is applied.

Still another object of the present invention is to provide a unitary convenient cooling package that is inert and capable of long shelf storage without deterioration but on the inter-mixing of the ingredients contained therein there is immediately initiated a mild cooling reaction so as to obviate shock on exposure thereto and which cooling progresses to a minimum temperature within a few minutes and maintains such for periods from one half hour to one and one half hours or longer.

A still further object of the present invention-is theprovision of a cooling package that on activation results in a semi-fluid gelatinous mass that conforms to the body to which it is applied, and Which,- on manipulation can be further activated to yield additional controlled cooling.

These and other objects of the present invention will be readily appreciated as the same becomes better understood by reference to the following'detailed description wherein specific examples of the package, composition and manner of using are illustrated. Whenever possible, alternative chemicals and modes of operation are discussed, but it will be recognized that various additional modifications can be made. without deviatingfrom the scope of the invention. l l i The above objects are accomplished by dividing the ingredients of a suitable composition and incorporating each of the divided parts into compartments of a segmented plastic bag, filling the same, storing the composition in this manner, and mixing the final composition immediately before a source of cooling is required.

A particularly suitable package for the present invention would be a plastic bag which is divided into equal nonconnecting compartments by installing a bag closure across the middle of said bag. The bag closure disclosed by Vance and Donnelly in US. Patent 3,060,985 would be suitable for this function.

In Part I of said bag, a water donating mixture of a saturated solution of a hydrated salt, a wetting agent and optionally a small excess of water is placed. The water prevents agglomeration of the salt and acts to initiate the cooling reaction as will be explained hereinafter.

Part II of said bag contains a mixture of salts which successively undergo an endothermic reaction and which form a gelatinous mass on dissolution in water. Optionally an agent which prevents caking or agglomeration may be added to the mixture of Part II and an additional substance that gels on dissolution may be present.

In operation, the dividing closure of the bag is removed and the chemical contents of the separate parts are intermixed. On contact of the small excess of water with the preferentially soluble salt of Part II an endothermic reaction is initiated and the cooling process and gelling and thickening of the total mixture begins. This initial cooling causes the water donating salt of Part I to liberate some of its bound water of hydration, which water dissolves more salt of Part II which results in more cooling. This donating and accepting process continues incrementally to give continuous cooling. The temperatures obtainable are below those obtained when ice is utilized for the same purpose.

At a latter time, as the bag is manipulated, the second endothermic solution reaction is initiated by the dissolution of the second salt present in Part II of the bag. The

conversion of the contents of the bag into a more fluid state contributes to the progress of the reaction, since it facilitates more intimate contact of the solvent with the remaining undissolved particles.

The solution reaction can be accelerated or retarded tains 125 to 175 parts by weight of a completely hydrated salt admixed with 5 to 10 parts by weight of Water and 1 to 10 parts of a wetting agent such as diamyl sodium sulfosuccinate. Also present may be three parts to 100 parts by weight of the total mixture of a gelling agent such as carbohydrates extracted from seaweed kelp, sodium alginate or other commercial gels and thickeners.

A preferable salt would be sodium thiosulfate in the following mixture:

Parts Na2S203 Diamyl sodium sulfosuccinate 5 Other hydrated salts such as particulate crystalline sodium carbonate, sodium sulfate, or sodium acetate will perform the same function and may be substituted for the sodium thiosulfate in the composition of Part I.

The water accepting composition of Part II contains as an essential component, to parts by weight of ammonium sulfamate plus 50 to-ZOO parts of a second salt and optionally 1 to 5 parts of Attapulgus clay or other suitable agents to prevent caking or agglomeration of the mixture during storage. The reason the sulfamate is essential is that this salt is preferentially dissolved in relation to the other salts to be enumerated, thus giving the extended cooling advantage and it is this salt that becomes gelatinous on solution giving the controlled positioning property to the final mixture.

The secondary soluble salt is preferably ammonium nitrate. An even more advantageous extended cooling can be obtained by coating part of this second salt with a substance that resists the solubilizing effect of the water from Part I thus increasing the time delay in attack of this chemical. An example of a salt in this form would be prelled ammonium nitrate, 75% of which is coated with diatomaceous earth (infusorial white fossil flour). The coating is only physical in nature and can be composed of other substances such as rosin, paraffin, kaolin clay, tricalcium phosphate, etc.

The preferred composition for Part II would be:

Parts by weight Powdered ammonium sulfamate 90 Attapulgus clay 2 Prelled ammonium nitrate 150 Other salts that will secondarily enter into the endothermic solution reaction are: Ammonium thiocyanate, ammonium chloride, ammonium sulfate, potassium chloride, potassium iodide, and potassium nitrate. The following table illustrates several compositions of Part I and corresponding compositions of Part II which on admixture give a double endothermic cooling reaction to yield a gelled mass according to the present invention. These compositions all contain wetting agents in Part I and an agent to prevent caking in Part II as previously comprising the steps of mixing a water donating mixture containing as a source of water, a completely hydrated salt with a water accepting mixture of ammonium sulfamate and at least one other differentially soluble salt to initiate a mild controlled endothermic reaction between said mixtures so as to form a semi-fluid gelatinous mass and applying said total mixture to the object to be cooled.

2. The method according to claim 1 wherein the completely hydrated salt of the water donating mixture is selected from the group consisting of sodium thiosulfate, sodium carbonate, sodium sulfate, and sodium acetate.

3. A method according to claim 2 wherein the hydrated salt is sodium thiosulfate.

4. The method according to claim 2 wherein the water donating mixture contains a slight excess of water and a wetting agent.

5. The method according to claim 1 wherein the additional soluble salt is at least one member selected from the group consisting of ammonium nitrate, ammonium thiocyanate, ammonium chloride, ammonium, sulfate, p0- tassium chloride, potassium iodide and potassium nitrate.

6. The method according to claim 5 wherein the additional soluble salt is ammonium nitrate.

7. A chemical cooling composition comprising a water donating mixture containing a completely hydra-ted salt and a water accepting mixture comprising ammonium sulfamate and at least one other differentially soluble salt whereby on admixing said mixtures, a mild controlled endothermic reactionis initiated to form a semirllld gelatinous mass.

8. The composition according to claim 7 wherein the completely hydrated salt is selected from the group consisting of sodium thiosulfate, sodium carbonate, sodium sulfate, and sodium acetate.

described. a 9. The composition of clalm 7 wherein the water do- Table Part I Part II Hydrated water donating salt Ammonium Secondary soluble salt H2O sulfamate, p.b.w. p.b.w. Salt P.b.w. Salt P.b.w.

1 Sodium thiosulfate 150 8 90 Ammonium thiocyanate. 175 d 150 8 90 Ammonium chloride 150 8 Ammonium sulfate 8 90 Potassium chloride 50 150 8 90 Potassium iodide 200 150 8 90 Potassium nitrate 100 150 8 90 Ammonium thiocyanate 150 8 9D Ammonium nitrate 150 150 8 90 Ammonium chloride 50 150 8 90 Ammonium thiocyanate. 175 150 8 90 Ammonium nitrate 150 150 8 9O Ammonium chloride 50 150 8 90 Ammonium thiocyanate. 175 150 8 90 Ammonium nitrate 150 150 8 90 Ammonium chloride 50 From the foregoing, it is understood that the compositions embodying the present invention are well suited to provide the following advantages:

Controlled cooling Controlled positioning of gelled mass Convenient package Extended periods of cooling nating mixture contains a slight excess of water and a wetting agent.

10. The composition of claim 7 wherein the additional soluble salt of the water accepting mixture is selected from the group consisting of ammonium nitrate, ammonium thiocyanate, ammonium chloride, ammonium sulfate, potassium chloride, potassium iodide, and potas sium nitrate.

11. The composition according to claim 10 wherein the additional soluble salt is ammonium nitrate.

- 12. The composition according to claim 7 wherein a portion of the additional soluble salt is coated.

13. The composition according to claim 11 wherein the water accepting composition contains an agent to prevent agglomeration of the salts.

14. A method according to claim 1 wherein the water donating mixture contains, in relative par-ts by weight, about 125-175 parts of a completely hydrated salt and a slight excess of water and the water accepting mixture contains 75-100 parts of ammonium sultamate and 200 parts of a second differentially soluble salt.

15. A composition according to claim 7 wherein the water donating mixture contains, in relative parts by weight, about 125-175 parts of a completely hydrated salt and a slight excess of water and the water accepting mixture contains -100 parts of ammonium sulfamate and 50-200 parts of a second differentially soluble salt.

16. A chemical cooling composition comprising, in relative parts by weight, a water donating portion containing a saturated solution of about -175 parts of hydrated sodium thiosulfate in a slight excess of water and a Water accepting portion containing 75-110 parts of ammonium sulfamate and 50-200 parts of a second differentially soluble salt whereby on admixture of said portions, a mild controlled endothermic reaction is initiated to form a semi-fluid gelatinous mass.

17. A composition according to claim 16 wherein the second difierentially soluble salt is ammonium nitrate, a portion of the particles of which are coated with a substance that resists the solubilizing effect of water.

6 18. A composition containing, in relative parts by weight, parts of hydrate sodium thiosulfate in a slight excess of water and 90 parts of powdered ammonium sulfarnate and 150 parts of prelled ammonium nitrate, 75% of the particles of which are coated with diatomaceous earth.

References Cited by the Examiner UNITED STATES PATENTS 2,109,952 3/38 Wyler. 2,8 82,692 4/59 Robbins 624 3,058,313 10/62 Robbins 62-4 OTHER REFERENCES Handbook of Chemistry & Physics, thirty-ninth edition, p. 486 (copy in Scientific Library), Chem. Rubber Pub. Co.

NORMAN YUDKOFF, Primary Examiner.

JULIUS GREENWALD, Examiner. 

1. A METHOD OF COOLING BY EFFECTING THE ENDOTHERMIC SOLUTION REACTION OF A MIXTURE OF DIFF ERENTIALY SOLUBLE SALTS COMPRISING THE STEPS OF MIXING A WATER DONATING MIXTURE CONTAINING AS A SOURCE OF WATER, A COMPLETELY HYDRATED SALT WITH A WATER ACCEPTING MIXTURE OF AMMONIUM SULFAMATE AND AT LEAST ONE OTHER DIFFERENTIALLY SOLUBLE SALT TO INITIATE A MILD CONTROLLED ENDOTHERMIC REACTION BETWEEN SAID MIXTURES SO AS TO FORM A SEMI-FLUID GELATINOUS MASS AND APPLYING SAID TOTAL MIXTURE TO THE OBJECT TO BE COOLED. 